Covered tray



NOV. 24, 1953 sc me 2,660,362

COVERED TRAY Filed March 8, 1948 2 Sheets-Sheet 1 Nov. 24, 1953 P. A.SCHILLING 2,660,362-

' COVERED TRAY Filed March 8, 1948 2 Sheets-Sheet 2 awe/WM PMAQSPatented Nov. 24, 1953 COVERED TRAY Paul A. Schilling, St. Paul, Minn.,assignor to Waldorf Paper Products Company, St. Paul, Minn a corporationof Minnesota Application March 8, 1948, Serial No. 13,547

2 Claims.

My invention relates to an improvement in cartons and deals moreparticularly with a carton closure and method of attaching the same.

For numerous years cartons have been formed in the nature of trays forcontaining foodstuffs and the like, and the carton and goods containedtherein are then wrapped in a transparent wrapping sheet. As a resultthe goods are supported in display position and at the same time areenclosed.

While such packages have many desirable characteristics, they usuallyhave the disadvantage that an expensive and complicated wrapping machineis required for sealing the goods. Such a wrapped carton also uses morewrapping material than is necessary to close the carton. In someinstances cartons have been provided with transparent windows andtransparent panels, but such cartons can not be filled as easily ascertain other types of constructions.

It is the object of the present invention to provide a carton whichcomprises a tray like body in which the goods to be packaged may beplaced and in covering the package with a sheet of cellophane which isheat sealed to the walls of the carton. As a result the tray may befilled in a convenient manner and may be quickly and easily closedwithout the necessity of wrapping the entire package.

A feature of the present invention lies in the provision of a trayhaving an open side such as an open top, and in applying a sheet oftransparent material over this open top and heat sealing the edgesthereof to the walls of the carton.

A further feature of the present invention lies in the provision of atray having flaps or flanges foldable to overlie a small portion of thetop of the carton near each end thereof and in sealing a sheet oftransparent material to these opposed flaps and to a pair of carton sidewalls to enclose the package contents. 6

A feature of the present invention lies in the provision of a cartonhaving a base and encircling side walls, in providing opposed flapsextending inwardly from two opposed side walls, and in anchoring a sheetof transparent sealing material to these inwardly extending flaps and tothe remaining side walls of the carton. As a result the sheet ofcovering material need only extend the length of the package and needonly be of sufficient width to extend over the top of the pack age andalong at least portions of opposed side walls.

These and other objects and novel features of my invention Will be moreclearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure 1 is a plan view of a blank of which a typical carton may beformed.

Figure 2 is a perspective view of a carton in sealed condition thereof.

Figure 3 is a longitudinal sectional view through the carton shown inFigure 2.

Figure 4 is a sectional view through the carton of Figure 3.

Figure 5 is a diagrammatic view showing the carton before the coveringsheet is applied thereto with the covering sheet positioned above thesame.

Figure 6 is a diagrammatic view showing the manner in which the coveringsheet may be folded over the sides of the carton and secured thereto.

Figure 7 is a plan view of the carton on the line 1-7 of Figure 6showing one type of heat sealing means used for sealing the coveringmember to the carton.

Figure 8 is a side elevational view of the carton in position againstthe top sealing members.

Figure 9 is a diagrammatic view showing the manner in which the sideedges of the covering member may be sealed.

The carton A illustrated in the drawings is only illustrative of onetype of carton which may be used to accomplish the desired result. Thecarton A includes a bottom panel i ii having side wall panels I I and I2foldably connected thereto along fold lines I3 and I l. The bottom panelIt is likewise connected to carton end walls l5 and It alongsubstantially parallel fold lines I1 and 19 respectively. Locking tabs20 and 21 are foldably connected to the end wall panel it alongextensions of the fold lines l3 and M. Similar locking flaps 22 and 23are foldably connected to the end wall panel l6 along extensions of thefold lines It and I4. These locking tabs 2&3, El, 22, and 23 areengageable in corresponding slots 24, 25, 26, and 21 in the side walls Hand I2. Flaps or flanges 29 and 30 are foldably connected to the upperedges of the end walls l5 and it along parallel fold lines 3| and 32.

When the blank illustrated in Figure 1 is erected, a carton is formedhaving a flat bottom panel and rectangularly arranged side and endwalls. The flaps 29 and 30 usually extend in coplanar relation to theend walls It and It to which they are attached, making these end wallssomewhat higher than the side walls during the filling of the carton ortray.

A carton or tray of the general type illustrated has been foundextremely desirable for containing many different types of merchandiseand have been lately found of unusual importance in containing bakerygoods. Such bakery goods may be placed in the trays in uncookedcondition and the goods may be actually baked while in the paper trays,thus eliminating considerable of the work and time ordinarily requiredin removing the bakery goods from their original receptacles and packingthem in different types of receptacles.

After the goods have been placed within the carton or tray and are readyfor the sealing operation the flaps 29 and 30 are folded intosubstantially parallel relation to the base panel 10 extending overportions of the contents of the package. A sheet of heat sealablematerial, which is preferably transparent in form is next placed overthe carton and the edges of this sheet 3! are folded to overlie the sidewalls II and 12 of the carton. The covering sheet is heat sealed to theflaps 29 and 30, to the side walls II and I2, and to the locking flaps20, 2!, 22, and 23, partially overlying the side walls. Alternatively,the locking panels may be provided on the side walls and the coveringsheet 33 may be heat sealed only to the flaps 29 and 30, and the sidewalls i l and 12.

When the carton is constructed as illustrated in Figure 1 of thedrawings, the general areas to which the sheet 33 is heat sealed areillustrated by the shaded areas appearing in this figure. Shaded areas34 and 35 are shown adjacent the fold lines 3! and. 32 connecting theflaps or flanges 29 and 3D to the end walls of the carton. Right angularshade areas 36, 31, 39, and 40 are provided on the locking flaps 20, 2|.22, and 23, respectively. Shaded areas 4i, and 42 are likewise shown onthe side walls ll and i2 near the fold lines l3 and I4. Thus it will beseen that the sheet 33 is marginally heat sealed about its entireperiphery to the flaps 29 and 30 and the walls of the carton.

Obviously the tray illustrated in Figure 1 of the drawings is only oneof a number of types of trays which would be suitable for my purpose. Itis only essential that the tray be provided with a bottom wall andencircling side walls, and flaps or flanges extending inwardly from twoopposed walls. There are some advantages in having the locking flaps oroverlapping flaps of the tray overlying the end walls of the cartonrather than the side walls thereof as the covering sheet 33 willobviously seal more readily to a flat surface.

The carton thus described has several advantages over most such cartons.In the first place the covering sheet need only be the length of thecarton and may actually be slightly shorter than the carton as it issealed at opposite ends to the flaps 29 and 30. The sealing area isshown closely adjacent the fold lines 34 and 32 as sealing pressure maymore readily be applied at these areas. Furthermore, the carton may beenclosed after the natural filling operation without the use ofcomplicated machinery. The sheets may be heat sealed to the carton wallswith a minimum of difficulty.

In Figures through 9 of the drawings I disclose diagrammatically onemethod by which the covering sheet may be secured to the carton. Thecarton A is shown in place upon a plunger 43 which is designed toelevate the carton. A sheet 33 of covering material of a heat scalabletype is positioned by any suitable means above the carton A. The plunger43 is elevated forcing the carton between the pair of folding members 44and 45. These members fold the sheet 33 to overlie parts of the sidewalls of the carton A as illustrated in Figure 6 of the drawings. Thusas the carton is plunged between the folding members 44 and 45 the sheetis folded into covering position.

As indicated in Figure '7 of the drawings the folding members 44 and 45may incorporate heat sealing bars which rub against the covering sheet33 and seal the sheet to the walls of the carton at either end thereof.The folding bar 44 may incorporate a pair of spaced heat sealing 43 and41 at opposite ends thereof which engage against the side walls of thecarton and form parts of the seal, as for example along the verticalpart of the areas 36 and 39. The folding member 45 may similarlyincorporate heat sealing bars 49 and 50 which engage the opposite sideof the carton and urge the covering sheet 33 against the carton and sealit thereto along portions of the areas 31 and 40. The remainder of thefolding members 44 and 45 may be of a relatively less heat conductivematerial or may be heat insulated from the bars 46, 41, 49, and 50.

The plunger 43 may then if desired, elevate the carton A into engagementwith heat sealing bars El and 52 which press against the top portion ofthe covering sheet and seal this sheet against the flaps 29 and 30 toform the heat sealed areas 31 and 32. The plunger presses the cartonagainst these heat sealing bars closely adjacent the fold lines 3! and32 so that the pressure may be withstood by the side walls of thecarton. Laterally reciprocable heat sealing bars 53 and 54 may moveinwardly toward the lower edges of the covering sheet 33 to seal thecovering sheet against the side walls of the carton. If the side wallsare continuous and smooth from one end to the other of the carton, thepressing surface of these bars may be similarly shaped. However, iflocking tongues are provided which overlie portions of the side walls ofthe carton, the sealing plates or bars 53 and 54 may be off-set tocompensate for this fact. The bars press the covering member against theside walls of the carton forming a seal along the areas 4! and 42.

If it is desired the entire side walls of the carton may be subjected toheat sealing plates as the carton moves upwardly. In other words, thewhole members 44 and 45 may be heated and pressure may be appliedthroughout the entire area of the side wallsof the carton to form a sealtherebetween. In this event the covering sheet need not extend to thebottom of the carton, but need only extend partly down the side walls ofthe carton from the top thereof. The use of auxiliary sealing plates 53and 54 has, however, been found desirableas the seal thus produced isclosely adjacent the lower end of the carton and the remainder of thedownwardly folded edges of the cover sheet are not subjected to hightemperature.

In accordance with the patent statutes, I have described the principlesof construction and operation of my carton closure and method ofattaching the same, and while I have endeavored to set forth the bestembodiment thereof, I desire to have it understood that obvious changesmay be made within the scope of the following claims without departingfrom the spirit of my inven-- tion.

I claim:

1. A carton including a tray comprising 2. rec tangular bottom panel andfour right angulariy arranged side walls connected thereto, meansconnecting said walls to hold said side walls in rectangular relation, apair of flaps foldably connected to the upper edges of two opposed ofsaid side walls and coextensive therewith, said flaps being bentinwardly into a plane parallel with the bottom panel, and a coveringsheet sealed to the outer surfaces of said flaps and extending beyondthe side edges thereof, said covering sheet being rectangular andsubstantially coextensive in length to the remaining two opposed sidewalls, the width of the covering sheet being substantially equal to thetotal of the width of the carton top and the height of both saidremaining side walls, said covering sheet extending down over saidremaining side walls and marginally sealed to the outer surfaces alongthe bottom and end edges thereof, the seal between said covering sheetand said flaps and remaining opposed side walls providing a continuousseal about substantially the entire periphery of said covering sheet.

2. The structure defined in claim 1 and in which the means connectingthe side walls comprises locking flaps on the first named opposed sidewalls overlying portions of the remaining opposed 6 side walls andinterlocked therewith, and in which the seal along the bottom edges andend edges of the remaining opposed side walls connects the locking flapsto the covering sheet.

' PAUL A. SCHILLING.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 952,802 Greene Mar. 22, 1910 1,176,115 Way et a1 Mar. 21, 19161,598,396 Scandore Aug. 31, 1926 1,786,743 Feybusch Dec. 30, 19301,923,065 Clemens Aug. 22, 1933 2,106,816 Shimizu et al Feb. 1, 19382,130,680 Ferenci Sept. 20, 1938 2,130,984 Larsen Sept. 20, 19382,226,089 Anthony Dec. 24, 1940 2,239,233 Hyndman Apr. 22, 19412,234,402 Frankenstein Mar. 11, 1942 2,474,543 McLellan June 28, 1949

